Podolyák, Zsolt EPJ Web Conf. 10.1051/epjconf/202327908001 08001 279 2023 2023 Understanding how the heavy chemical elements are made in the astrophysical $r$-process requires information on both the properties of the nuclei involved and that of the environment. The availability of experimental information on the neutron-rich N∼126 nuclei is discussed, with emphasis on phenomena specifically relevant to this region: the large role of first-forbidden $\beta$ decays, and that of the $\Delta n = 0$ selection rule in Gamow-Teller decays. The development of nuclear data bases by combining different theoretical approaches is suggested.